[ Bob Baker wrote in 021109 MMDigest:
 [> ... we experienced more than a few CDs which caused an
 [> unacceptable number of "drop-outs" (missed notes) when
 [> played through both units into our test Pianocorder System.

Hi Bob,  You may look into Manchester encoding.  This is the basis
for the Pianocorder and the CD information [data encoding method].
Also consider the voltage levels of the solenoids.

Don Dusenbury